one approach is to use reshape(), e.g., # suppose that 'dat' is your data.frame, then res <- reshape(dat, direction = "wide", idvar = "Q", timevar = "S") res[is.na(res)] <- 0 res
I hope it helps. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm ----- Original Message ----- From: "Des Callaghan" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Tuesday, September 12, 2006 8:43 AM Subject: [R] Transformation of a data frame > Dear R-helpers, > > Apologies in advance for this (probably) simple question. I've > searched the > R Archive and can't seem to find a solution to my problem. > > I have a data frame of vegetation quadrat data with the following > format: > > Q S C > 1 A 5 > 1 B 10 > 1 C 50 > 1 D 10 > 2 A 20 > 2 E 10 > 2 C 40 > 3 D 5 > 3 F 1 > 3 G 5 > 3 B 75 > > Where Q is the sample (vegetation quadrats), S is the species and C > is the > percentage cover of each species within the sample. I wish to > transform > this into a community data matrix for analysis within the vegan > package, > which needs the following data frame format: > > Q A B C D E F G > 1 5 10 50 10 0 0 0 > 2 20 0 40 0 10 0 0 > 3 0 75 0 5 0 1 75 > > I can't manage to do this transformation so your help would be much > appreciated. Thanks very much in advance. > > All the best, > Des > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
